Advertisement

COOLING MODALITY EFFECTIVENESS AND MORTALITY ASSOCIATED WITH PREHOSPITAL CARE OF EXERTIONAL HEAT STROKE CASUALTIES

Published:December 19, 2022DOI:https://doi.org/10.1016/j.jemermed.2022.12.015

      Abstract

      Background

      Cold-water immersion is the gold standard for field treatment of an exertional heat stroke (EHS) casualty. Practical limitations may preclude this method and ice sheets (bed linens soaked in ice water) have emerged as a viable alternative. Laboratory studies suggest that this is an inferior method; however, the magnitude of hyperthermia is limited and may underestimate the cooling rate in EHS casualties.

      Objective

      Our aim was to determine the prehospital core cooling rate, need for continued cooling on arrival to the emergency department, and mortality rate associated with ice sheet use.

      Methods

      De-identified retrospective data were obtained from emergency medical services (EMS) and included presence or absence of altered mental status, cooling measures applied prior to EMS arrival, and time and core temperature (Tc; rectal) on-scene and on hospital arrival. Cooling rate was calculated from time and temperature data. Mortality data were obtained from the US Army Combat Readiness Center.

      Results

      There were 462 casualties that met inclusion criteria. The cooling rate for the entire sample was 0.07°C ± 0.08°C · min−1. EHS casualties with an observed initial Tc < 39°C had an en route cooling rate of 0.03°C ± 0.04°C · min−1 vs. initial Tc ≥ 39°C cooling rate of 0.16°C ± 0.08°C · min−1. There was one fatality due to EHS, for a mortality rate of 0.20% (95% CI 0.01–1.20%).

      Conclusions

      The cooling rate in EHS casualties with initial Tc ≥ 39°C was approximately double that reported in laboratory studies. The observed mortality rate was comparable with casualties treated with cold-water immersion. Our data suggest that ice sheets provide a viable alternative when practical constraints preclude cold-water immersion.

      Keywords

      To read this article in full you will need to make a payment

      Purchase one-time access:

      Academic & Personal: 24 hour online accessCorporate R&D Professionals: 24 hour online access
      One-time access price info
      • For academic or personal research use, select 'Academic and Personal'
      • For corporate R&D use, select 'Corporate R&D Professionals'

      Subscribe:

      Subscribe to Journal of Emergency Medicine
      Already a print subscriber? Claim online access
      Already an online subscriber? Sign in
      Institutional Access: Sign in to ScienceDirect

      REFERENCES

        • Leon LR
        • Bouchama A.
        Heat stroke.
        Compr Physiol. 2015; 5: 611-647
        • Epstein Y
        • Heatstroke Yanovich R.
        N Engl J Med. 2019; 380: 2449-2459
        • Tustin AW
        • Cannon DL
        • Arbury SB
        • Thomas RJ
        • Hodgson MJ.
        Risk Factors for heat-related illness in U.S. workers: an OSHA case series.
        J Occup Environ Med. 2018; 60: e383-e389
        • Shibolet S
        • Coll R
        • Gilat T
        • Sohar E.
        Heatstroke: its clinical picture and mechanism in 36 cases.
        Q J Med. 1967; 36: 525-548
        • DeMartini JK
        • Casa DJ
        • Stearns R
        • et al.
        Effectiveness of cold water immersion in the treatment of exertional heat stroke at the falmouth road race.
        Med Sci Sports Exerc. 2015; 47: 240-245
        • Casa DJ
        • McDermott BP
        • Lee EC
        • Yeargin SW
        • Armstrong LE
        • Maresh CM.
        Cold water immersion: the gold standard for exertional heatstroke treatment.
        Exerc Sport Sci Rev. 2007; 35: 141-149
        • Kanda J
        • Nakahara S
        • Nakamura S
        • et al.
        Association between active cooling and lower mortality among patients with heat stroke and heat exhaustion.
        PLoS One. 2021; 16e0259441
        • Douma MJ
        • Aves T
        • Allan KS
        • et al.
        First aid cooling techniques for heat stroke and exertional hyperthermia: a systematic review and meta-analysis.
        Resuscitation. 2020; 148: 173-190
        • McDermott BP
        • Casa DJ
        • Ganio MS
        • et al.
        Acute whole-body cooling for exercise-induced hyperthermia: a systematic review.
        J Athl Train. 2009; 44: 84-93
        • Heled Y
        • Rav-Acha M
        • Shani Y
        • Epstein Y
        • The Moran DS.
        "golden hour" for heatstroke treatment.
        Mil Med. 2004; 169: 184-186
        • Roberts WO
        • Armstrong LE
        • Sawka MN
        • Yeargin SW
        • Heled Y
        • O'Connor FG
        ACSM expert consensus statement on exertional heat illness: recognition, management, and return to activity.
        Curr Sports Med Rep. 2021; 20: 470-484
      1. TRADOC Regulation 350-29 Prevention of Heat and Cold Casualties.
        US Army Training and Doctrine Command, Fort Eustis, VA2012 (July 6, 2012. Report No.: Contract No.: TRADOC Regulation 350-29. Accessed December 27, 2022)
        • Filep EM
        • Murata Y
        • Endres BD
        • Kim G
        • Stearns RL
        • Casa DJ.
        Exertional heat stroke, modality cooling rate, and survival outcomes: a systematic review.
        Medicina (Kaunas). 2020; 56: 589
        • McDermott BP
        • Casa DJ
        • O'Connor FG
        • et al.
        Cold-water dousing with ice massage to treat exertional heat stroke: a case series.
        Aviat Space Environ Med. 2009; 80: 720-722
        • Butts CL
        • Spisla DL
        • Adams JD
        • et al.
        Effectiveness of ice-sheet cooling following exertional hyperthermia.
        Mil Med. 2017; 182: e1951-e1957
        • Belval LN
        • Casa DJ
        • Adams WM
        • et al.
        Consensus statement-prehospital care of exertional heat stroke.
        Prehosp Emerg Care. 2018; 22: 392-397
        • Jardine JF
        • Stearns RL
        • McClaine KB
        • Casa DJ.
        Heroic, lifesaving measures are unnecessary when optimal cooling is provided for exertional heat stroke victims.
        J Emerg Med. 2020; 59: 145-146
        • Drobatz KJ
        • Macintire DK.
        Heat-induced illness in dogs: 42 cases (1976-1993).
        J Am Vet Med Assoc. 1996; 209: 1894-1899
        • Mellor PJ
        • Mellanby RJ
        • Baines EA
        • Villiers EJ
        • Archer J
        • Herrtage ME.
        High serum troponin I concentration as a marker of severe myocardial damage in a case of suspected exertional heatstroke in a dog.
        J Vet Cardiol. 2006; 8: 55-62
        • Krum SH
        • Osborne CA.
        Heatstroke in the dog: a polysystemic disorder.
        J Am Vet Med Assoc. 1977; 170: 531-535
        • Bursey MM
        • Galer M
        • Oh RC
        • Weathers BK.
        Successful management of severe exertional heat stroke with endovascular cooling after failure of standard cooling measures.
        J Emerg Med. 2019; 57: e53-e56
        • Armstrong LE.
        Exertional heatstroke in American football: persistent battles, research frontiers.
        Curr Sports Med Rep. 2010; 9: 126-127
        • Mok G
        • DeGroot DW
        • Hathaway NE
        • Bigley DP
        • McGuire CS.
        Exertional heat injury: effects of adding cold (4°C) intravenous saline to prehospital protocol.
        Curr Sports Med Rep. 2017; 16: 103-108
        • DeGroot DW
        • Rappole CA
        • McHenry P
        • Englert RM.
        Seasonal trends for environmental illness incidence in the U.S. Army.
        Mil Med. 2022; 187: e672-e677
        • DeGroot DW
        • Henderson KN
        • O'Connor FG
        Exertional heat illness at Fort Benning, GA: unique insights from the Army Heat Center.
        Med Surveill Month Rep. 2022; 22: 2-7
        • Department of the Army
        Army Regulation 40-501 Standards of Medical Fitness.
        Department of the Army, 2011